Njingang Ketchate Cédric Gervais, Tiam Kapen Pascalin, Madiebie-Lambou Inesse, Fokwa Didier, Chegnimonhan Victorin, Tchinda René, Tchuen Ghislain
Laboratory of Mechanics, University of Douala, Douala, Cameroon.
URISIE, University Institute of Technology Fotso Victor, University of Dschang, P.O Box 134, Bandjoun, Cameroon.
Heliyon. 2023 Jan 16;9(1):e12962. doi: 10.1016/j.heliyon.2023.e12962. eCollection 2023 Jan.
Nowadays ferrofluids (magnetic nanofluids) are at the center of many researches because of their major biomedical applications such as drug delivery and cancer treatment. The effects of chemical reaction, temperature gradient induced mass transfer and concentration gradient induced heat transfer on the stability of ferrofluid flow are of great importance. This paper deals with a stability analysis of a ferrofluid composed of blood as base fluid and magnetic nanoparticles. The study integrates the effects of chemical reactions, the effects of mass transfer (Soret effect), the effects of heat transfer (Dufour effect) and the effects of the Buoyancy force. The flow is exposed to a magnetic field and thermal radiation. A system of eigenvalue equations governing the evolution of disturbances is derived by assuming a normal mode analysis. This system of equations is then solved numerically by the method of collocation. It appears from this study that the addition of nanoparticles to the blood increases its inertia, which dampens the amplitude of the disturbances and stabilizes the flow. The Casson parameter affects the stability of the flow by increasing the amplitude of the disturbances, which reflects its destabilizing effect. It appears from this study that taking into account the non-Newtonian nature of blood is very important when modeling the dynamics of the system because it shows more important and very different results than when blood is treated as a Newtonian fluid. The chemical reaction between the fluid and the nanoparticles leads to the redistribution of disturbances within the flow, which amplifies the instabilities and reflects the destabilizing character of the chemical reaction. On the other hand, temperature gradient induced mass transfer effects and concentration gradient induced heat transfer effects play an essential role on the stability of the flow because they attenuate the amplitude of the disturbances in the flow. The Darcy number exhibits a stabilizing effect on the flow. It appears from this analysis that the porosity of the medium increases the contact surface between the fluid and the nanoparticles. Buoyancy forces, thermal radiation parameter and wave number contribute to the stability of the flow. The magnetic field through the Lorentz force decreases the kinetic energy of the flow, which dissipates the disturbances and thus reflects the stabilizing character of the magnetic field. It should be noted that heat and mass transfer on magnetohydrodynamic flows through porous media taking into consideration the effect of chemical reaction appears in many natural and artificial transport processes in several branches of science and engineering applications. This phenomenon plays an important role in the chemical industry, power and cooling industry for drying, chemical vapor deposition on surfaces, cooling of nuclear reactors and petroleum industry. The effects of thermal radiation, mass and heat transfer are used in many situations in biomedical engineering and aerospace engineering.
如今,铁磁流体(磁性纳米流体)因其在药物输送和癌症治疗等主要生物医学应用方面成为众多研究的核心。化学反应、温度梯度引起的传质以及浓度梯度引起的传热对铁磁流体流动稳定性的影响至关重要。本文研究了以血液为基液、磁性纳米颗粒组成的铁磁流体的稳定性分析。该研究综合考虑了化学反应的影响、传质效应(索雷特效应)、传热效应(杜福尔效应)以及浮力效应。流体流动处于磁场和热辐射作用下。通过假设进行正常模态分析,推导了控制扰动演化的特征值方程组。然后采用配置法对该方程组进行数值求解。从这项研究可以看出,向血液中添加纳米颗粒会增加其惯性,从而抑制扰动幅度并使流动稳定。卡森参数通过增加扰动幅度来影响流动稳定性,这反映了其使流动不稳定的作用。从这项研究可以看出,在对系统动力学进行建模时,考虑血液的非牛顿性质非常重要,因为与将血液视为牛顿流体相比,它会呈现出更重要且截然不同的结果。流体与纳米颗粒之间的化学反应导致流动中扰动的重新分布,这会放大不稳定性并反映出化学反应的使流动不稳定特性。另一方面,温度梯度引起的传质效应和浓度梯度引起的传热效应在流动稳定性方面起着至关重要的作用,因为它们会减弱流动中扰动的幅度。达西数对流动具有稳定作用。从该分析可以看出,介质的孔隙率增加了流体与纳米颗粒之间的接触面积。浮力、热辐射参数和波数对流动稳定性有贡献。通过洛伦兹力的磁场会降低流动的动能,从而消散扰动,进而反映出磁场的稳定特性。需要注意的是,考虑化学反应影响的通过多孔介质的磁流体动力学流动中的传热和传质现象出现在科学和工程应用的多个分支中的许多自然和人工传输过程中。这种现象在化学工业、电力和冷却工业中的干燥、表面化学气相沉积、核反应堆冷却以及石油工业中都起着重要作用。热辐射、传质和传热效应在生物医学工程和航空航天工程的许多情况下都有应用。